The present invention provides a fail-safe control system particularly adapted for an internal-combustion-engine-driven snowmobile, but is also adapted for application to high speed outboard motor driven boats, motorcycles, engine driven riding lawnmowers, and similar units (all called "vehicles" in this specification) where the operator normally guides and operates the engine of the vehicle from throttle lever in an exposed position such that it can be jammed by a foreign object getting into the throttle lever assembly, or it will freeze and stick, or otherwise fail to decelerate the engine while operating at what could be a dangerous speed. Snowmobiles in particular have become popular and useful both for commercial and sports purposes and operating in cold weather, snow, and often in the brush these are particularly vulnerable to jamming, freezing, or the like in the throttle system such that the safety of the operator is in jeopardy if the vehicle cannot be stopped when the operator loses control of the unit.
This problem has been attacked in switches for such vehicles to insure the safety of the operator and U.S. Pat. No. 3,672,344 which issued June 27, 1972 on an application filed Sept. 11, 1970, U.S. Pat. No. 3,789,938 which issued Feb. 5, 1974 on an application filed Apr. 24, 1972, as well as U.S. Pat. No. 3,798,402 issued Mar. 19, 1974 on an application filed Apr. 19, 1972 are the answers of these patentees to a so-called safety system for such a vehicle. However, none of these prior switch systems provide the necessary safety to the operator for no one takes care of the situation wherein the engine is operating at high speed and the operator is unable to move the throttle lever and decelerate or stop the engine because of some one of the conditions described above, or the operator is thrown from the vehicle. There are also mechanical deficiencies in these prior switch systems independently of the lack of complete safety, but the latter is the significant problem which the present invention solves while providing a more sturdy, compact switch and control mechanism in a single housing with a throttle lever therewith and with the housing mounted on the handlebar of the vehicle.
One of the important uses for snowmobiles is in the brush or in rough country, or in other environments where the exposed position of the control and guiding mechanism in the open cockpit is particularly vulnerable to twigs, branches, and other foreign materials becoming wedged in the throttle control system at the handlebar. Furthermore, snowmobiles are operated in exceedingly cold climates where heavy gloves are necessary for the operator, and these can become jammed in the throttle mechanism without fault of the driver. The control system of the present invention takes care of these situations, and the switches thereof act to open the ignition circuit for the engine and stop the engine should the driver lose control because of the conditions mentioned, and this system causes the engine to decelerate to idle condition should the operator lose control by falling from the vehicle while operating at high speeds.